Decimals


Multiplying Decimals

To multiply decimals, line up the numbers, not the decimal points. Then multiply the numbers as usual.

Count the number of digits in both numbers that lay to the right of the decimal points.

Place the decimal point in the answer so that there are an equal number of digits to the right of the decimal point. The answer should contain that number of digits to the right of the decimal point.







To Multiply 7.6 X 2.4

7.6 has 1 digit to the right of its decimal point.

2.4 also has 1 digit to the right of its decimal point.

1 + 1 = 2.

The answer should have 2 digits to the right of its decimal point.


7.6
X
2.4






304
152








18.24


(Place the Decimal Point so there are 2 Digits to the Right)



Since the decimal points do not need to line up, there is no reason to add any zeroes as temporary place holders.






To multiply 4.12 X 3.4 line up the numbers and count the total number of decimal points.


4.12
X
3.4






1648
1236






14.008


(Place the Decimal Point so there are 3 Digits to the Right)








Remove any trailing zeroes from the final answer.

5.4 x 2.5


5.4
X
2.5






270
108






13.50
=
13.5








Include a leading zero if necessary.

1.2 x 0.3


1.2
X
0.3






.36
=
0.36







RULE

Multiplying Decimals.

Multiply the numbers as usual.

Count the number of Decimal Points in both numbers.

Move the Decimal Point of the answer the same number of places.

Remove any Trailing Zeroes.

Use a Leading Zero if necessary.